Non-corrosive bromochloromethane fire extinguisher composition and fire extinguishercontaining the composition



Jan. 28, 1958 E. s. BUCKLEY 2,321,257

. NON-CORROSIVE BROMOCHLOROMETHANE FIRE EXTINGUISHER v COMPOSITION ANDFIRE EXTINGUISHER CONTAINING THE COMPOSITION Filed Dec. 9, 1.955

INVENTOR DWAUD Q5001 5y ATTORNEY United States Patent O i NON-CORROSIVEBROMOCI-ILOROMETHANE FIRE EXTINGUISHER COMPOSITION AND FIRE EXTINGUISHERCONTAINING THE COMPOSITION Edward G. Buckley, Morris Plains, N. 1.,assignor, by

mesne assignments, to The Fyr-Fyter Company, Dayton, Ohio, a corporationof Ohio Application December 9, 1955, Serial No. 552,052

7 Claims. (Cl. 169- -31) J This invention relates to fire-extinguishingcompositions and is more particularly concerned with afire-extinguishing-composition which is passive toward metals such as-stainless steels.

The eifectiveness of halogenated hydrocarbons as fireextinguishingfluids is well known and liquid fire-extinguishing compositionsconsisting of one or more halogenated hydrocarbons have been extensivelyused. It is also known, however, that such liquids tend to undergodecomposition d-uring storage, particularly in the presence of smalltraces of water, with the formation of acidic substances which readilycorrode metals. Over the years many compounds have been tested for theircorrosion inhibiting activity whenused with halogenated hydrocarbons andsome of these compounds have been found to be somewhat elfective. It hasbeen found, however, that :corrosi'on inhibitors are specific in theiractivity and that compounds which are effective when used ,with one typeof halogenated hydrocarbon are not necessarily effective with othertypes. Furthermore, While such inhibitors may prevent or retardcorrosion of some metals or alloys, 'they have little or no effect uponmore readily corroded metals. Brass is generally the best protected byconventional inhibitors since this alloy has a certain degree of naturalresistance to corrosion by halogenated hydrocarbons. As a result,containers commonly used for halogenated hydrocarbon fire-extinguishingcompositions have been made of brass. Brass is, however, a relativelysoft alloy and is comparatively expensive, particularly when itthas tobe of heavygauge towithstand'gas pressures in pressure-operatedextinguishers. Furthermore, such. extinguishers have moving parts toprovide the necessary valves and even slight corrosion tends tointerfere with proper operation of these parts.

From, the standpoint of manufacture, efliciency and economy, stainlesssteel is a highly advantageous material from which to construct afire-extinguisher. It has not been used, however, because none of thecorrosion inhibitors heretofore proposed for use in fire-extinguishingcompositions has been fully elfective in protecting stainless steelagainst halogenated hydrocarbons. Further more, bromochloromethane is aparticularly effective fireextinguishing compound but it has a highlycorrosive action upon metals, particularly stainless steel, in thepresence of even very small quantities of water. Since the last tracesof water cannot, from a practical standpoint, be removed frombromochloromethane suitable for fire-extinguishing purposes, the use ofstainless steel containers for holding such bromochloromethane has notheretofore been possible because commonly employed- 2,821,257 PatentedJan. 28,1958

Specific gravity 1.9l0-l.940 25 C.

Boiling range 595% distills in 2. 0 C. temperature range including 67.8C.

Acidity Not more than 1.0 ml. of 0.01 N NaOH to neutralize ml. of watershaken for 10 mins. with equal volume of bromochloromethane.

Free halogens None.

Non-volatile residueru Not more than 0.004 g./ 100 ml.

Water Not more than 0.04%.

To provide the non-corrosive fire-extinguishing composition of theinvention there is added to bromochloro= methane, e. g. the commercialproduct identified above, one-half to two percent, preferably onepercent by weight of ethylene oxide or propylene oxide or mixturesthereof. Ethylene oxide and propylene oxide are soluble inbromochloromethane and are incorporated in it merely by simple mixing.While both ethylene oxide and propylene oxide are effective, propyleneoxide is preferred because it is liquid at room temperature and can behandled some what more easily.

When bromochloromethane fortified against corrosive activity withethylene oxide or propylene oxide in accordance with the inventionisstored in a fabricated stainless steel fire-extinguisher casing, thecorrosive action normally encountered when bromochloromethane is broughtinto contact with stainless steel is absent and the composition may bestored for long periods of time without damage to the casing and withoutclogging or plugging of movable parts such as valves. There is shown inthe accompanying drawing a fabricated fire-extinguishing casing which istypical of the type which has caused difliculty in the past when made ofstainless steel or other metal or alloy normally subject to corrosion bybromochloromethane in the presence of small quantities of water.

The single figure of the drawing is a sectional view taken on a verticalplane through the center of the extinguisher casing.

In the drawing there is shown a casing 10 having a welded top portion 12formed with a central opening in which is secured a sleeve 14.Threadedly engaged in sleeve 14 and sealed by a gasket 15 is a valveshell 16 defining a valve seat 18 and carrying at its lower end adownwardly-extending tube 20 formed with a head portion 21 threadedlyengaged with shell 16. Reciprocatable in shell 16 is a valve memberhaving a stem portion 22 sealed in the shell, by means of an O-ringgasket 24 seated in a groove 26, and provided with a head 28 holding awasher 30 in place against a shoulder 32. A spring 34 normally urged thevalve member outwardly to seat washer 30 against seat 18 to preventescape of fluid from casing 10.

The upper end of valve stem 22 is provided with an actuating handlemember 36 by means of which the valve may be unseated by the user tocause discharge of the fire-extinguishing fluid. The upper portion ofthe valve shell 16 is surrounded by a hood 38 provided with an opening40 communicating with a bore 42 which extends through hood 38 and thewall of shell 16 and opens into the interior of the valve shell. Theextinguisher is pressurized by admitting compressed air or othercompressed gas through opening 40 and bore 42, and the extinguishercontents are discharged through these passageways under the action ofthe compressed gas when the valve is unseated.

It will be seen that an extinguisher such as described above has manythreaded members and has a valve which must move freely if theextinguisher is to operate properly in an emergency. The seriousconsequences which may result from a jammed or frozen fire-extinguisherare obvious. The extinguisher must also be freely separable forrecharging purposes and if the threads are corroded it is apparent thatthe necessary separation of parts may be impossible without damage ordestruction of the extinguisher.

Corrosion tests, however, have shown that ethylene oxide and propyleneoxide fully protect stainless steel against corrosion by moistbromochloromethane for long periods of time. The term stainless steel asused herein has its conventional meaning and includes the various alloysof iron and chromium which may also contain nickel and small percentagesof silicon, molybdenum, tungsten, or copper. Stainless steels areclassified and identified in accordance with their content of alloyingmetals and are grouped in numerically designated series such as the 300series, e. g. 301, 304 and 310, and the 400 series, e. g. 410, 420 and430. Typical stainless steels are described in detail and identified,for example, in Marks Mechanical Engineers Handbook (th ed.), beginningat page 559.

Strips of welded 300 series, e. g. 310, stainless steels and strips ofunwelded 400 series, e. g. 420, stainless steels were immersed inbromochloromethane containing about 2.5% water and corresponding stripswere immersed in another portion of the same bromochloromethane to which1% ethylene oxide had been added and in another portion to which 1%propylene oxide had been added. After two months exposure to sunlightthe strips immersed in the non-inhibited bromochloromethane wereseverely corroded whereas the strips immersed in the inhibitedbromochloromethane samples showed no corrosion whatsoever.

In another test, strips of welded 300 series, e. g. 301, stainlesssteels were immersed in bromochloromethane containing 2-3% water and thesamples were refluxed four hours a day for a month. In a comparativetest, using strips of the same steels and using a portion of the samebromochloromethane to which 1% propylene oxide was added and a portionto which 1% ethylene oxide had been added, the samples were given thesame reflux treatment. The strips were then examined and those exposedto the non-inhibited bromochloromethane were found to be severelycorroded Whereas the strips which had been exposed to the inhibitedbromochloromethane portions showed no evidence of corrosion.

What I claim and desire to secure by Letters Patent is:

l. A fire-extinguisher composition consisting essentially ofbromochloromethane and one-half of two percent by Weight of a member ofthe group consisting of ethylene oxide and propylene oxide.

2. A fire-extinguishing composition consisting essentially ofbromochloromethane and about one percent by weight of a member of thegroup consisting of ethylene oxide and propylene oxide.

3. A fire-extinguishing composition consisting essentially ofbromochloromethane and one-half to two percent by weight of ethyleneoxide.

4. A fire-extinguishing composition consisting essentially ofbromochloromethane and one-half to two percent by weight of propyleneoxide.

5. A fire-extinguishing composition consisting essentially ofbromochloromethane containing at least traces of water and one-half totwo percent by weight of a member of the group consisting of ethyleneoxide and propylene oxide.

6. A fire-extinguishing composition consisting essentially ofbromochloromethane containing up to 2.0% by weight water andone-half totwo percent by weight of a member of the group consisting of ethyleneoxide and propylene oxide.

7. A fire-extinguishing package comprising a valved casing of stainlesssteel containing a fire-extinguishing composition consisting essentiallyof bromochloromethane and one-half to two percent by weight of a memberof the group consisting of ethylene oxide and propylene oxide.

References Cited in the file of this patent UNITED STATES PATENTS2,273,515 Dachlauer Feb. 17, 1942 2,419,915 Priest et a1 Apr. 29, 19472,573,320 Eckelmann Oct. 30, 1951 PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 2, 821,257 January 28, 1958 Edward C Buckley ofthe above numbered patent requiring correction and that the said LettersPatent should read as corrected belowa Column 2, line 68, for urged"read ==urges-=-=; column 4, line 14, for "of two percent" read to twopercentfi,

Signed and sealed this 6th day of May 1958.

( A Afloat:

KARL Ho AXLINE of Patents U. S. DEPARTMENT OF COMMERCE PATENT OFFICEERTIFKQATE F CRRECTEN Patent No, 2,821,257 January 28, 1958 Edward G,Buckley Ii; is hereby certified that error appears in the printedspecification of the above numbred patent requiring correction and thatthe said Letters Patent sheuld read as corrected belown Column 2, line68, for "urged" read ==Urges-=-=; column 4, line 14, for "of twopercent" read. to two percent== Signed and sealed this 6th day of May1.9581,

(SEAL) Atfiest:

KARL v AZLINE R0ET E. WATSQN Attsstifig Gfiimar Csmissimer 6f Peatems

1. A FIRE-EXTINGUISHER COMPOSITION CONSISTING ESSENTIALLY OFBROMOCHLOROMETHANE AND ONE-HALF OF TWO PERCENT BY